1. Field of the Invention
The invention relates to a method and device for sealing a puncture wound in a blood vessel. More particularly, the invention relates to a collapsible biodegradable collagen plug for sealing a puncture wound in a blood vessel that minimizes the risk of blood vessel entry and that maintains pressure on the puncture site in the blood vessel.
2. Description of the Prior Art
In certain medical procedures, such as cardiac catheterization, dilation and counterpulsation, a catheter or other device is inserted into an artery, most commonly by percutaneous methods, and then fed through the arterial tree to the site where needed, frequently, the region of the heart. The site usually selected for insertion of the catheter is the groin, because the femoral artery in that region is relatively easy to locate.
These procedures are normally initiated by insertion of an angiographic needle, followed by passing a guide wire through that needle into the artery. The needle is then removed leaving the guide wire in place. Next, a sheath-dilator set is passed over the guide wire into the artery in order to enlarge the opening sufficiently to permit entry of the catheter or other device. The dilator is then removed, leaving the sheath or guide cannula in place. The catheter or other device can then be inserted through the cannula with full confidence that when it emerges from the distal end it will be within the lumen of the artery.
It should be understood that the subject invention is independent of the blood vessel involved. While it is expected that the femoral artery will be the most commonly used blood vessel, use of other arteries as well as veins is anticipated as well.
After a procedure, for example, counterpulsation, has been completed, the sheath must be removed and the wound closed. Often, this can be accomplished simply by the application of digital pressure, generally augmented by the use of a pressure dressing. Customarily, pressure must be applied for at least 1/2 hour, and frequently for much longer than that. While pressure dressings often suffice, it is not uncommon for additional devices, such as sandbags, to be needed. In addition, during this period the patient must be immobilized, lest movement interfere with the closing process. Because of the pressure required, the time during which it must be applied and the need for immobilization, the procedure is painful and uncomfortable. The procedure also requires prolonged personal attention of a health care professional. Finally, wound closures accomplished in this manner are prone to reopen unexpectedly long after closure appears to have been completed. Patients are therefore often required to remain in the hospital for 24 hours or longer.
A device for sealing the wound, overcoming many of the above mentioned problems, is disclosed in U.S. Pat. No. 5,591,204 and is known in the medical field under Datascope Corp.'s VasoSeal.RTM. trademark. The VasoSeal.RTM. product comprises a charge of hemostatic material and a hollow sheath adapted to pass through the tissue channel of a patient, the sheath having a cross sectional profile larger than the puncture in the patient's blood vessel. The Vasoseal.RTM. product places the hemostatic material in the hollow sheath and advances the hemostatic material through the sheath to the outside of the vessel wall around the puncture. The preferred embodiment of the hemostatic material is a compressed cylinder or plug of collagen in which the distal most portion is fluffed. The plug is designed to mushroom slightly when the plug contacts the exterior wall of the artery and the stiff proximal end lodges in the tissue tract thus holding the expanded distal end in place on the artery. Aside from providing greater puncture area coverage the fluffing of the distal end also serves the purpose of exposing more hemostatic fibers to the blood thus allowing the hemostatic material to react more readily with the blood.
U.S. Pat. Nos. 5,330,445 and 5,552,840 disclose a tubular sheath which is slidably disposed over a tubular medical device and which is positioned at a body access site. The sheath is deposited within a patient to assist in sealing the wound caused by the tubular medical device and inhibit internal and external bleeding. Despite the wound sealing assistance provided, these wound sealing sheaths suffer a number of drawbacks, including the possibility of allowing the sheath to enter the artery. The sheath may enter the artery if the distal tip of the sheath does not mushroom out far or is not large enough to engage the puncture site at the exterior wall of the artery. In this instance the proximal end of the plug transmits the insertion force provided by the insertion device to the distal end of the plug allowing the distal tip to penetrate the puncture site and thus enter the artery. Entrance of the plug into the artery is dangerous for a number of reasons. Entrance of the distal tip of the plug, or the entire plug, into the artery obstructs blood passage in the artery and emboli formation on the plug further obstructs blood flow. Furthermore, emboli may break off the distal tip of the plug and flow downstream. Free floating emboli must be removed surgically to prevent decreased circulation to distal extremities.
Another major disadvantage of the above mentioned wound sealing devices is that they rely primarily on the friction force between the patient's tissue tract wall and the plug and slight swelling of the plug itself to maintain the position of the plug and its pressure on the puncture site. As a result, the plug may be dislodged from the tissue tract with minimal force. Furthermore, the pressure on the artery, required for rapid puncture closure, is lost quickly after the insertion device is removed.
While the foregoing wound closure devices may be suitable for the particular purposes employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.